Partner portal Onboarding Tracker Open action. Returns a login link to the entity's onboarding application that skips the applicant's one-time passcode and carries a live bearer token, so treat it as a credential. The response is sent with Cache-Control: no-store, and the link is left out of the API log and the note. The entity must be in the partner's book, in Application Pending, and have an onboarding application: an entity that does not exist, one outside the book and one with no status get the same not-found error as the drawer, and one in another stage or without an application gets an invalid-action error. If the onboarding app cannot be reached or fails, the request fails with an integration error. Writes an account note (a partner note for a child partner) naming the portal user, without the link. Requires a partner portal session (bearer token) of an Admin user and the AccountOnboardingFormAccess permission; Viewer and Support users are rejected.